The present invention relates to the field of robotics and remotely guided vehicles. More particularly, the present invention relates to an automatic system for supplementing human direction of a servo-controlled, remotely guided vehicle.
Remotely operated platforms have been employed for a variety of applications dating back to World War II. Recent advances in the applicable technologies have brought about an even greater interest in such systems for use in hazardous environments, such as those found in the nuclear power industry, underwater search and recovery, fire-fighting, and bomb disposal, to name but a few. Often, however, the advantages afforded by removing the operator from a dangerous situation are significantly offset by the subsequent difficulties encountered in controlling the remote platform. Thus, the number of practical applications for tele-operated systems are limited to those for which the perils associated with direct human exposure justify the operational difficulties associated with such systems.
One of the fundamental problems with tele-operated systems is control of vehicle motion based on visual feedback provided to the operator, as for example, by an onboard camera. Loss of depth perception and impaired visual acuity are perhaps the most important factors that limit the potential effectiveness of such systems.
Much work has been done over the past decade to improve the man-machine interface for tele-operated systems in an attempt to achieve a higher operational equivalence ratio, which can be loosely defined as the amount of time it takes a human to directly perform a series of tasks, divided by the amount of time it would take an operator to perform the same tasks remotely. One type of remote telepresence system provides stereo vision as well as binaural hearing to give the operator a stronger sense of actually being in the working environment. Head-coupled displays have been employed to further enhance this feeling, wherein a pair of high-resolution cameras on the remote (slave) end are positioned in real-time in accordance with the pan and tilt movements of a helmet worn by the operator at the (master) control station. The helmet is equipped with miniature monitors to relay the video from the left and right cameras to the left and right eyes of the operator, thus providing some degree of depth perception. As the operator turns his head toward elements of interest in the scene being viewed, the remote slave positions the cameras accordingly to achieve the desired input. While the 3-D capability thus provided is a decided improvement over monocular vision, the negative side effects include extremely high operator fatigue, a tendency to induce nausea in some operators, higher bandwidth requirements in the control loop, and significantly enhanced system complexity.
Therefore, there is a need for a system which supplements human operator control of a remote controlled mobile platform by automatically adjusting the speed and direction of the platform as a function of environmental congestion. A further need exists for a system which greatly reduces operator fatigue over present teleoperated mobile platforms, and which eliminates the possibility of collisions with obstacles in the path of the platform.